Global Patent Index - EP 0178821 A2

EP 0178821 A2 19860423 - Programmable automatic cable equalizer.

Title (en)

Programmable automatic cable equalizer.

Title (de)

Programmierbarer automatischer Kabelentzerrer.

Title (fr)

Egaliseur de câble automatique programmable.

Publication

EP 0178821 A2 19860423 (EN)

Application

EP 85307041 A 19851002

Priority

US 65877384 A 19841009

Abstract (en)

57 The circuit (10) has a gain section which includes a first AGC circuit (12). The output of the gain section goes to a signal shaping section which includes a biquadratic filter (24), a summer (45), and a second AGC circuit (40). The two AGC circuits (12, 40) are controlled by respective separate peak detectors (20, 50) and are noninteracting. For "short" cables, only the first AGC circuit (12) is active. For "long" cables, the first AGC circuit (12) is set at its gain breakpoint and the second AGC circuit (40) alone has active control. The shaping section includes a biquadratic filter (24) which is a tandem arrangement of a low-pass filter (26), an inverter (28), and an integrator (32). The low pass output (35) of the integrator (32) is connected to the noninverting (+) input of the a summing amplifier (45). The input (42) of the second AGC circuit (40) is connected to the band pass output (33) of the inverter (28), while its output (44) is connected to the inverting input (-) of the summing amplifier (45). The input of the second peak detector (50) is connected to the output (48) of the summing amplifier (45) and its output is connected to the control node (52) of the second AGC circuit (40). Operational amplifiers (G1,G2,G3,G4) of the first peak detector (20), the low-pass filter (26), the integrator (32), and the summing amplifier (45) are designed to be programmable by means of decoders (22, 36, 38, 46) to permit the equalizer (10) to accommodate different data rates.

IPC 1-7

H04B 3/04

IPC 8 full level

H04B 3/04 (2006.01); H04L 25/48 (2006.01)

CPC (source: EP US)

H04B 3/04 (2013.01 - EP US)

Designated contracting state (EPC)

BE DE FR GB IT NL SE

DOCDB simple family (publication)

EP 0178821 A2 19860423; EP 0178821 A3 19870107; AU 4837585 A 19860417; AU 557588 B2 19861224; CA 1238698 A 19880628; JP S6194418 A 19860513; US 4606043 A 19860812

DOCDB simple family (application)

EP 85307041 A 19851002; AU 4837585 A 19851008; CA 491872 A 19850930; JP 22387285 A 19851009; US 65877384 A 19841009